In early 2018,the Boliden Garpenberg operation implemented an optimized control strategy as an addition to the existing ventilation on demand system.The purpose of the strategy is to further minimize energy use for ma...In early 2018,the Boliden Garpenberg operation implemented an optimized control strategy as an addition to the existing ventilation on demand system.The purpose of the strategy is to further minimize energy use for main and booster fans,whilst also fulfilling airflow setpoints without violating constraints such as min/max differential pressure over fans and interaction of air between areas in mines.Using air flow measurements and a dynamical model of the ventilation system,a mine-wide coordination control of fans can be carried out.The numerical model is data driven and derived from historical operational data or step changes experiments.This makes both initial deployment and lifetime model maintenance,as the mine evolves,a comparably easy operation.The control has been proven to operate in a stable manner over long periods without having to re-calibrate the model.Results prove a 40%decrease in energy use for the fans involved and a greater controllability of air flow.Moreover,a 15%decrease of the total air flow into the mine will give additional proportional heating savings during winter periods.All in all,the multivariable controller shows a correlation between production in the mine and the ventilation system performance superior to all of its predecessors.展开更多
An accurate fault location algorithm for double-circuit series compensated lines is presented.Use of two-end unsynchronized measurements of current and voltage signals is considered.The algorithm applies two subroutin...An accurate fault location algorithm for double-circuit series compensated lines is presented.Use of two-end unsynchronized measurements of current and voltage signals is considered.The algorithm applies two subroutines,designated for locating faults on particular line sections,and additionally the procedure for selecting the valid subroutine.The subroutines are formulated with use of the generalized fault loop model and the distributed parameter line model is applied.Performed ATP-EMTP based evaluation has shown the validity of the derived fault location algorithm and its high accuracy.展开更多
This paper seeks to expand on the role for future homes in relation to automation,sustainability,healthcare and manufacturing.The world is changing and the home along with it.Services provided in the home will no long...This paper seeks to expand on the role for future homes in relation to automation,sustainability,healthcare and manufacturing.The world is changing and the home along with it.Services provided in the home will no longer act separately but will be all the more integrated into each other as new connections between services increase the value for residents in the home.This paper presents some of the possible integrated services and a close-up of the networked manufacturing service.A conceptual communication infrastructure for the service is finally provided.展开更多
Integration of distributed generation(DG)can change the fault current level and direction in the distribution system,which affects the related protection system.In order to limit the negative impact of DG integration ...Integration of distributed generation(DG)can change the fault current level and direction in the distribution system,which affects the related protection system.In order to limit the negative impact of DG integration and upgrade the protection system performance,an intelligent coordinated protection and control strategy is proposed.A cost based optimization method is adopted to minimize the operation costs of possible solutions.Its aim is to define the optimal relay settings for the present operation condition,and the most suitable control mode of converter based wind turbine DG.Case studies on a hardware in the loop real time simulation platform demonstrate the proposed protection strategy.展开更多
文摘In early 2018,the Boliden Garpenberg operation implemented an optimized control strategy as an addition to the existing ventilation on demand system.The purpose of the strategy is to further minimize energy use for main and booster fans,whilst also fulfilling airflow setpoints without violating constraints such as min/max differential pressure over fans and interaction of air between areas in mines.Using air flow measurements and a dynamical model of the ventilation system,a mine-wide coordination control of fans can be carried out.The numerical model is data driven and derived from historical operational data or step changes experiments.This makes both initial deployment and lifetime model maintenance,as the mine evolves,a comparably easy operation.The control has been proven to operate in a stable manner over long periods without having to re-calibrate the model.Results prove a 40%decrease in energy use for the fans involved and a greater controllability of air flow.Moreover,a 15%decrease of the total air flow into the mine will give additional proportional heating savings during winter periods.All in all,the multivariable controller shows a correlation between production in the mine and the ventilation system performance superior to all of its predecessors.
文摘An accurate fault location algorithm for double-circuit series compensated lines is presented.Use of two-end unsynchronized measurements of current and voltage signals is considered.The algorithm applies two subroutines,designated for locating faults on particular line sections,and additionally the procedure for selecting the valid subroutine.The subroutines are formulated with use of the generalized fault loop model and the distributed parameter line model is applied.Performed ATP-EMTP based evaluation has shown the validity of the derived fault location algorithm and its high accuracy.
文摘This paper seeks to expand on the role for future homes in relation to automation,sustainability,healthcare and manufacturing.The world is changing and the home along with it.Services provided in the home will no longer act separately but will be all the more integrated into each other as new connections between services increase the value for residents in the home.This paper presents some of the possible integrated services and a close-up of the networked manufacturing service.A conceptual communication infrastructure for the service is finally provided.
基金supported by Norwegian University of Science and Technology.
文摘Integration of distributed generation(DG)can change the fault current level and direction in the distribution system,which affects the related protection system.In order to limit the negative impact of DG integration and upgrade the protection system performance,an intelligent coordinated protection and control strategy is proposed.A cost based optimization method is adopted to minimize the operation costs of possible solutions.Its aim is to define the optimal relay settings for the present operation condition,and the most suitable control mode of converter based wind turbine DG.Case studies on a hardware in the loop real time simulation platform demonstrate the proposed protection strategy.
